基于OBDD的可修航天测控系统任务可靠性分析

基于顺序二元决策图(OBDD)理论,针对航天测控系统(TT&C系统)特点定义了新的OBDD数据结构,提出了一种考虑设备可修的TT&C系统任务可靠性分析方法.通过将各测控站的时间窗口划分为不同阶段,分析各阶段内设备逻辑关系并构建阶段OBDD模型,然后将所有阶段OBDD模型合并为最终的任务OBDD模型.采用连续时间Markov链(CTMC)分析可修设备的状态转移行为,基于新的OBDD数据结构给出了任务可靠性计算算法.与Markov方法和仿真方法的对比分析结果表明:所提出的方法能够精确计算设备可修的TT&C系统任务可靠性,设备数量多于30个时算法效率高于Markov方法. 

Mission reliability analysis of repairable space TT&C system based on OBDD

Based on the ordered binary decision diagram (OBDD) theory, a new OBDD data structure in view of the characteristics of space telemetry, tracking and command system (TT&C system) was defined, and an approach to mission reliability analysis of repairable TT&C system was proposed. By dividing time windows of each station into phases, component logic relationship of each phase was analyzed, and the OBDD model of each phase was established. Then the final mission OBDD model was established by combining all single phase OBDD models together. Continuous time Markov chain (CTMC) was adopted to analyze the transition behaviors of each repairable component, and the mission reliability calculating algorithm was presented based on the new OBDD data structure. The result of a contrastive analysis with Markov method and simulation method reveals that: the proposed method can be used to analyze the mission reliability of repairable TT&C system accurately; the algorithm efficiency is higher than Markov method when there are more than 30 components.